Lab 12. Magnetism and Atomic Structure: What Relationships Exist Between the
Electrons in a Substance and the Strength of Magnetic Attraction?
Introduction
The structure of atoms is both simple and complex at the same time. The bulk of the mass of an atom is
located in the nucleus, where protons and neutrons are relatively evenly distributed. Outside an atom’s
nucleus are electrons, which are negatively charged particles that are attracted to the positively charged
nucleus. Electrons inhabit regions of space known as orbitals. These regions represent the probable
position of an electron at any given point in time. Each orbital has a unique shape and can hold only two
electrons. Each orbital also has a defined energy level.
At the first energy level is the 1s orbital. The “1”
indicates that the orbital is in the energy level
closest to the nucleus, and the “s” describes the
3-D representation of s and p electron orbitals
shape of the orbital; s orbitals are spheres. At the
second energy level, there is a second s orbital
called the 2s orbital. This orbital is similar to the 1s
orbital except that the region where there is the
greatest chance of finding the electron is farther out
from the nucleus. There are similar orbitals at
higher energy levels (e.g., 3s, 4s, and 5s). At the
second energy level there are also p orbitals; a p
orbital looks like two balloons tied together. There
are three different p orbitals that point at right
angles to each other. These orbitals are called px, py,
and pz. The p orbitals at the second energy level are
Electron configuration diagram for iron
called 2px, 2py, and 2pz (the 2 indicates that they are
at the second energy level). There are also p orbitals
at higher energy levels (e.g., 3px, 3py, 3pz, 4px, 4py,
and 4pz). In addition to s and p orbitals, there are
two other sets of orbitals at higher energy levels. At
the third energy level, for example, there is a set of
five d orbitals (with complicated shapes and names)
as well as the 3s and 3p orbitals. At the third energy
level there are a total of nine orbitals. At the fourth
energy level, there are seven f orbitals as well the 4s,
4p, and 4d orbitals. Figure L12.1 illustrates the 1s,
2s, and 2p orbitals.
The electron configuration of any atom can be
determined using the Aufbau principle. According to this principle, electrons fill low-energy orbitals before
they fill higher-energy ones. Electrons, however, are mutually repulsive, so individual electrons will
occupy different orbitals at the same energy level before sharing the same orbital at a specific energy
level. This tendency to occupy different orbitals at the same energy level, which is called Hund’s rule,
helps to minimize the repulsions between electrons and makes the atom more stable. As an example,
consider the electron configuration of iron as illustrated in Figure L12.2. In this figure orbitals are
represented as horizontal lines with the electrons in them depicted as arrows; up and down arrows are
used to indicate that the electrons have different spins. The 26 electrons that are present in an iron atom
are distributed across 15 orbitals according to the Aufbau principle and Hund’s rule. The 1s, 2s, 2p, 3s,
and 4s orbitals are completely filled. The five 3d orbitals are each occupied by at least one electron, and
only one of these orbitals is completely filled.
FIGURE L12.1
FIGURE L12.2
The electron configuration of the atoms found within a substance will affect its magnetic properties.
Many pure substances, besides iron metal, are attracted to a strong magnetic field. These substances are
said to be paramagnetic. Substances that are not affected by strong magnetic fields are said to be
diamagnetic. Past experiments with electricity and magnetism have demonstrated a connection between
the magnetic properties of a substance and the movement of electrons. In the quantum mechanical model,
one of the energy states of electrons is related to the electron’s spin (ms = −1/2 or +1/2). This electron spin
produces a magnetic field with electrons spinning in opposite directions that have reverse magnetic
poles. Paired electrons always have the opposite spin from their partner, which means their magnetic
fields cancel out each other’s effect. Unpaired electrons can spin in either direction and can change that
direction when interacting with the magnetic fields of other unpaired electrons. In this investigation you
will explore the relationship between electron configuration and magnetism in ionic compounds.
Your Task
Determine how electron configuration affects the magnetic properties of a substance.
The guiding question of this investigation is, What relationships exist between the electrons in a
substance and the strength of magnetic attraction?
Materials
You may use any of the following materials during your investigation:
Consumables
Equipment
Vials containing copper(II) chloride (Cu2+),
iron(II) chloride (Fe2+), manganese(II) chloride
(Mn2+), and zinc chloride (Zn2+)
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Empty vial
Neodymium-iron-boron magnet
Electronic balance
Plastic collar for electronic balance plate
Splints or rods
Safety Precautions
Follow all normal lab safety rules. Your teacher will explain relevant and important information about
working with the chemicals associated with this investigation. Caution: The neodymium-iron-boron magnet
that you will use in this investigation is very powerful but extremely brittle. DO NOT test the magnet on the
exposed metal at your laboratory station or bring anything metallic near your magnet. In addition, take the
following safety precautions:
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Wear indirectly vented chemical-splash goggles and chemical-resistant gloves and apron while in
the laboratory.
Wash your hands with soap and water before leaving the laboratory.
Investigation Proposal Required?
 Yes
 No
Getting Started
The first step in your investigation will be to create a device
that you can use to measure the magnetic properties of
different substances. Figure L12.3 shows how you can use
an electronic balance to measure magnetic attraction. Once
you have created your magnetic attraction measuring
device, you will need to develop a procedure to determine
how electron configuration affects the magnetic properties
of the different chlorides that are available. Before you can
design your procedure, however, your group will need to
determine what type of data you need to collect, how you
will collect the data, and how you will analyze the data. To
determine what type of data you need to collect, think about the
following questions:
FIGURE L12.3
Magnetic attraction measuring device
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What type of measurements will you need to record during your investigation?
When will you need to make these measurements?
To determine how you will collect the data, think about the following questions:
What comparisons will you need to make?
How will you hold other variables constant?
How will you use reduce measurement error?
How will you keep track of the data you collect and how you will organize it?
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To determine how you will analyze the data, think about the following questions:
What are the similarities and differences in the electron configurations for each of the metal ions
you used?
What type of graph or table could you create to help make sense of your data?
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Connections to Crosscutting Concepts, the Nature of Science, and the Nature of Scientific
Inquiry
As you work through your investigation, be sure to think about
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the relationship between structure and function,
how system models contribute to understanding science,
the difference between laws and theories in science, and
how scientific knowledge can change over time in light of new evidence.
Initial Argument
Once your group has finished collecting and
analyzing your data, you will need to develop an
initial argument. Your argument must include a
claim, which is your answer to the guiding
question. Your argument must also include
evidence in support of your claim. The evidence is
your analysis of the data and your interpretation
of what the analysis means. Finally, you must
include a justification of the evidence in your
argument. You will therefore need to use a
scientific concept or principle to explain why the
evidence that you decided to use is relevant and
important. You will create your initial argument
on a whiteboard. Your whiteboard must include
all the information shown in Figure L12.4.
FIGURE L12.4
Argument presentation on a whiteboard
Argumentation Session
The argumentation session allows all of the groups to share their arguments. One member of each group
stays at the lab station to share that group’s argument, while the other members of the group go to the
other lab stations one at a time to listen to and critique the arguments developed by their classmates. The
goal of the argumentation session is not to convince others that your argument is the best one; rather, the
goal is to identify errors or instances of faulty reasoning in the initial arguments so these mistakes can be
fixed. You will therefore need to evaluate the content of the claim, the quality of the evidence used to
support the claim, and the strength of the justification of the evidence included in each argument that you
see. To critique an argument, you might need more information than what is included on the whiteboard.
You might therefore need to ask the presenter one or more follow-up questions, such as:
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How did your group collect the data? Why did you use that method?
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What did your group do to make sure the data you collected are reliable? What did you do to
decrease measurement error?
What did your group do to analyze the data, and why did you decide to do it that way? Did you
check your calculations?
Is that the only way to interpret the results of your group’s analysis? How do you know that your
interpretation of the analysis is appropriate?
Why did your group decide to present your evidence in that manner?
What other claims did your group discuss before deciding on that one? Why did you abandon
those alternative ideas?
How confident are you that your group’s claim is valid? What could you do to increase your
confidence?
Once the argumentation session is complete, you will have a chance to meet with your group and
revise your original argument. Your group might need to gather more data or design a way to test one or
more alternative claims as part of this process. Remember, your goal at this stage of the investigation is to
develop the most valid or acceptable answer to the research question!
Report
Once you have completed your research, you will need to prepare an investigation report that consists of
three sections that provide answers to the following questions:
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What question were you trying to answer and why?
What did you do during your investigation and why did you conduct your investigation in this
way?
What is your argument?
Your report should answer these questions in two pages or less. The report must be typed and any
diagrams, figures, or tables should be embedded into the document. Be sure to write in a persuasive
style; you are trying to convince others that your claim is acceptable or valid!